Charles Hakes Fort Lewis College1

Charles Hakes Fort Lewis College2

Charles Hakes Fort Lewis College3 Chapter 2 Light and Matter

Charles Hakes Fort Lewis College4 Outline Logistics Review Light and Matter Waves

Charles Hakes Fort Lewis College5 Logistics Test 1 will be Friday next week. 3 minute “paragraphs” Re-use pages add dates Avoid “about” say something specific. iClicker registration ( ?) Tutor (!?)

Charles Hakes Fort Lewis College6 Your Folder Full name on the tab BIG name on the front Major on upper right Class on lower left A comment about yourself on the lower right Inside - your most recent, or current, math class (subject, course number, and year taken.) Include your daily three minute papers! You can reuse pages, just add the date. Say something specific.

Charles Hakes Fort Lewis College7 Review What was the most important thing you learned? The smaller the parallax shift of an object the further away the object is. There are 2  radians in a circle.

Charles Hakes Fort Lewis College8 Radians Not just an extra button on your calculator 2  radians in a circle Conversion formula 2  rad = 360° Conversion practice page on-line!

Charles Hakes Fort Lewis College9 Small Angle Approximation Angle must be in radians Angle must be small (opposite << adjacent) Then:   sin(  )  tan(  )

Charles Hakes Fort Lewis College10 Small Angle Approximation For small angles in radians: angle = baseline/distance

Charles Hakes Fort Lewis College11 Small Angle Approximation For small angles in radians: angle = baseline/distance or distance = baseline/angle or baseline = angle*distance

Charles Hakes Fort Lewis College12 If your baseline is 25cm, and you observe a parallax shift of 0.01 rad. The distance to the object is: 1: 2.5cm 2: 2500cm 3: 25000cm

Charles Hakes Fort Lewis College13 More Precisely P-2b Measuring Distances with Geometry

Charles Hakes Fort Lewis College14 Small Angle Approximation If you know the size of an object, you can determine it’s distance using the same triangle formulas distance = baseline/angle This time the “baseline” is the known diameter of the object and the angle is the observed apparent “size” of the object.

Charles Hakes Fort Lewis College15 You see your friend in the distance and measure that they “subtend” 1 degree. How many radians is that? A) 57 B) 1.6 C).034 D).017 E).012

Charles Hakes Fort Lewis College16 You know your friend is 1.6m tall, and that they “subtend” radians. How far away are they? A) 94m B) 0.27m C) 163m D) 57m E) 106m

Where does the full moon rise in Durango on June 21? A) North of east (by more than 5°) B) Within 5.2° of due east C) South of east (by more than 5°) D) Not enough information

Where does the full moon rise in Durango on June 21? A) North of east (by more than 5°) B) Within 5.2° of due east C) South of east (by more than 5°) D) Not enough information Charles Hakes Fort Lewis College

Charles Hakes Fort Lewis College19 Chapter 2 The Ring Nebula

Charles Hakes Fort Lewis College20 Chapter 2 The Ring Nebula

Charles Hakes Fort Lewis College21 Figure 2.1 Andromeda Galaxy

Charles Hakes Fort Lewis College22 Radiation Astronomical objects are VERY far away. How do we learn about them?

Charles Hakes Fort Lewis College23 Radiation Astronomical objects are VERY far away. How do we learn about them? Answer - light electromagnetic radiation rays waves

Charles Hakes Fort Lewis College24 Figure 2.8 Electromagnetic Spectrum

Charles Hakes Fort Lewis College25 Figure 2.2 Water Wave

Charles Hakes Fort Lewis College26 Waves Waves - a disturbance making a distinctive, repeating pattern. The disturbance is what moves - not the medium.

Charles Hakes Fort Lewis College27 Types of Waves Transverse waves in solids example earthquakes

Charles Hakes Fort Lewis College28 Types of Waves Transverse waves in solids example earthquakes Compressional waves in solids or liquids or gasses example sound

Charles Hakes Fort Lewis College29 Types of Waves Transverse waves in solids example earthquakes Compressional waves in solids or liquids or gasses example sound Electromagnetic waves in nothing (vacuum)

Charles Hakes Fort Lewis College30 Wave Properties Period how long one cycle is units are seconds Frequency = 1/period units are Hertz (per second, 1/sec, or sec -1 ) wavelength wave speed (velocity) amplitude

Charles Hakes Fort Lewis College31 Figure 2.3 Wave Properties

Charles Hakes Fort Lewis College32 Wave Properties Wavelength x frequency = velocity

Charles Hakes Fort Lewis College33 Wave Properties Wavelength x frequency = velocity = c

Charles Hakes Fort Lewis College34 Which wave is fastest when traveling through space? A) Light from a light bulb B) Green laser C) FM radio waves D) X-rays from a dentist office E) They are all the same speed

Charles Hakes Fort Lewis College35 The Speed of Light 299, km/sec (~= 3.00x10 8 m/s) It’s not just a good idea. It’s the law!

Charles Hakes Fort Lewis College36 History of The Speed of Light

Charles Hakes Fort Lewis College37 Figure 2.4 Charged Particles

Charles Hakes Fort Lewis College38 Figure 2.5 Magnetism

Charles Hakes Fort Lewis College39 Figure 2.6 Electromagnetic Wave

Charles Hakes Fort Lewis College40 Figure 2.7 Visible Spectrum

Charles Hakes Fort Lewis College41 Figure 2.8 Electromagnetic Spectrum

Charles Hakes Fort Lewis College42 Which list is in the correct order of electromagnetic radiation wavelength, going from shortest to longest? A) infrared, ultraviolet, gamma, radio B) gamma, x-ray, ultraviolet, visible C) radio, infrared, visible, ultraviolet D) radio, x-ray, ultraviolet, visible E) red, violet, blue, green

Charles Hakes Fort Lewis College43 Which is correct A) wavelength / velocity = frequency B) wavelength / velocity = period C) wavelength * frequency = period D) wavelength * velocity = frequency

Charles Hakes Fort Lewis College44 Three Minute Paper Write 1-3 sentences. What was the most important thing you learned today? What questions do you still have about today’s topics?